Imagine if 30 years ago someone were to tell you that the Civil War wasn't about slavery, and to prove it showed you a quote like this one from General Robert E. Lee, here taken from Confederate American Pride:
There are few, I believe, in this enlightened age, who will not acknowledge that slavery is an institution of a moral and political evil
Assuming that you believed the quote to be accurate, you might be left scratching your head and wondering why this seems so contradictory to what you've always heard. You're probably not going to run to the library to research Robert E. Lee quotes to see the context from which that quote was taken. Which is, by the way, via Wikipedia and Rad Geek,
In this enlightened age, there are few I believe, but what will acknowledge, that slavery as an institution, is a moral & political evil in any Country. It is useless to expatiate on its disadvantages. I think it however a greater evil to the white man than to the black race, & while my feelings are strongly enlisted in behalf of the latter, my sympathies are more strong for the former. The blacks are immeasurably better off here than in Africa, morally, socially & physically. The painful discipline they are undergoing, is necessary for their instruction as a race, & I hope will prepare & lead them to better things. How long their subjugation may be necessary is known & ordered by a wise God.
Of course, 30 years ago, few people would have heard the misleading out-of-context quote to begin with, so the Internet helps spread lies along with the truths that debunk them. Which is why there are still so many Confederate battle flag lovers who think the flag isn't a symbol of racism.
I know that such true believers exist, but if they honestly do their research, they should have a change of heart.
People with busy lives who don't think much about the flag and what it has stood for may be forgiven for not knowing the truth. But for anyone willing to make a stand, the Internet leaves little excuse for such ignorance. By the time someone is yelling "baaa, baaa" into a bullhorn to drown out the truth from counter-protesters at a Confederate rally, or has compiled a website full of out-of-context quotes and misleading facts, that person is not a true believer. That person is a liar.